This invention relates in general to cutting equipment, and in particular to a cutting assembly and method for cutting openings in a sheet of thermoformed containers or cells.
Thermoforming is the conversion of a plastic sheet into a shaped article by heating the sheet, placing the sheet in a mold, and applying vacuum and/or pressure so that the sheet conforms to the shape of the mold. Many different types of articles can be made by thermoforming, including various types of containers and cells. For example, thermoformed containers are often used for holding produce such as strawberries. Thermoformed horticultural trays include cells for holding bedding plants and other horticultural products. The containers and cells for produce, horticultural products and similar products are sometimes provided with openings for air circulation and liquid drainage.
When thermoformed containers and trays are made for holding produce, horticultural products and similar products, a plurality of containers or cells are usually formed in a single sheet. Then, individual openings are created in each of the containers or cells formed in the sheet. One conventional method of creating the openings is to use a punch and die apparatus. However, the cost of creating the openings with a punch and die apparatus is undesirably high. Another conventional method is to burn the openings in the containers or cells. However, burning the plastic sheet presents safety issues and produces undesirable fumes.
Therefore, it would be advantageous to provide a cutting assembly and method for cutting openings in a sheet of thermoformed containers or cells which is less costly than the conventional punch and die method. It would also be advantageous to provide a cutting assembly and method which does not present safety or environmental issues.